424 Circular Xo. 2. 



In some cases the fungicide is to be applied to the seed in order to 

 destroy the spores that chng to the outside of it. In the case of a few 

 diseases, the parasite enters the seed before it ripens and there remains 

 dormant from one season to the next. The appHcation of high temper- 

 ature by means of hot water has proved effective in destroying the para- 

 site without serious injury to the germinating abiHty of the seed. The 

 loose smut of wheat and the naked smut of barley are good examples. 



In a few cases, the application of certain chemicals to the soil effectively 

 controls diseases of the roots or stems of plants. The few parasites con- 

 trolled in this way are soil lovers, living for at least a part of their lives 

 as saprophytes on the decaying materials or humus of the soil. Some 

 soil fungi are effectively destroyed by steam sterilization. This is 

 practicable chiefly in the greenhouse. 



The preparation of the common fungicides is neither difficult nor 

 expensive. Below are given concise directions for preparing those most 

 commonly in use at present, together with lists of the more common 

 diseases which careful experiments have shown to be effectively con- 

 trolled by them. For detailed directions for applying them to any par- 

 ticular disease, address an inquiry to the Plant Pathologist, New York 

 State College of Agriculture, Ithaca, N. Y. 



SPRAY MIXTURES. 

 Bordeaux Mixture. 



Materials. Copper sulfate (blue vitriol) costing 7 to 10 cents per pound; good 

 stone lime costing around a dollar a barrel; and water. These are to be put together 

 in different proportions depending upon the crop to be sprayed and the time when 

 the application is to be made. The proportion is usually expressed in the following 

 way, 5-5-50 which means: Copper sulfate 5 lbs.; lime 5 lbs. ; and water 50 gallons. 

 Other proportions are used for some diseases and under certain conditions. These 

 are Indicated by other numbers in the formula, as 2-4-50, etc. The copper sulfate 

 is the active agent in the mixture. The lime is added to neutralize the caustic 

 action of the copper sulfate which would otherwise bum the leaves or fruit of the 

 plant. 



Formula 5-5-50. 



To prepare the mixture. Dissolve the 5 lbs. of copper sulfate in 30 or 40 gallons 

 of water by suspending the crystals in a gunny sack just beneath the surface of the 

 water, as the dissolved vitriol settles quickly to the bottom. Prepare the hme 

 (5 lbs.) by slacking it with hot water adding the water slowly so that the lime 

 crumbles into a fine powder. When completely slacked, i.e. entirely powdered, 

 add 5 or 6 gallons of cold water to make a rather thin milky solution. When the 

 vitriol is all dissolved stir it thoroughly and pour into it the lirne milk which has been 

 thoroughly stirred. Add enough water to make 50 gallons. One solution, pre- 

 ferably the copper sulfate as indicated above should always be much diluted. 



